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6417 | ashmew2 | 1 | /* |
2 | * jcapimin.c |
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3 | * |
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4 | * Copyright (C) 1994-1998, Thomas G. Lane. |
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5 | * This file is part of the Independent JPEG Group's software. |
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6 | * For conditions of distribution and use, see the accompanying README file. |
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7 | * |
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8 | * This file contains application interface code for the compression half |
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9 | * of the JPEG library. These are the "minimum" API routines that may be |
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10 | * needed in either the normal full-compression case or the transcoding-only |
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11 | * case. |
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12 | * |
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13 | * Most of the routines intended to be called directly by an application |
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14 | * are in this file or in jcapistd.c. But also see jcparam.c for |
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15 | * parameter-setup helper routines, jcomapi.c for routines shared by |
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16 | * compression and decompression, and jctrans.c for the transcoding case. |
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17 | */ |
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18 | |||
19 | #define JPEG_INTERNALS |
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20 | #include "jinclude.h" |
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21 | #include "jpeglib.h" |
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22 | |||
23 | |||
24 | /* |
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25 | * Initialization of a JPEG compression object. |
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26 | * The error manager must already be set up (in case memory manager fails). |
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27 | */ |
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28 | |||
29 | GLOBAL(void) |
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30 | jpeg_CreateCompress (j_compress_ptr cinfo, int version, size_t structsize) |
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31 | { |
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32 | int i; |
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33 | |||
34 | /* Guard against version mismatches between library and caller. */ |
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35 | cinfo->mem = NULL; /* so jpeg_destroy knows mem mgr not called */ |
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36 | if (version != JPEG_LIB_VERSION) |
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37 | ERREXIT2(cinfo, JERR_BAD_LIB_VERSION, JPEG_LIB_VERSION, version); |
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38 | if (structsize != SIZEOF(struct jpeg_compress_struct)) |
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39 | ERREXIT2(cinfo, JERR_BAD_STRUCT_SIZE, |
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40 | (int) SIZEOF(struct jpeg_compress_struct), (int) structsize); |
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41 | |||
42 | /* For debugging purposes, we zero the whole master structure. |
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43 | * But the application has already set the err pointer, and may have set |
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44 | * client_data, so we have to save and restore those fields. |
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45 | * Note: if application hasn't set client_data, tools like Purify may |
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46 | * complain here. |
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47 | */ |
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48 | { |
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49 | struct jpeg_error_mgr * err = cinfo->err; |
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50 | void * client_data = cinfo->client_data; /* ignore Purify complaint here */ |
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51 | MEMZERO(cinfo, SIZEOF(struct jpeg_compress_struct)); |
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52 | cinfo->err = err; |
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53 | cinfo->client_data = client_data; |
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54 | } |
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55 | cinfo->is_decompressor = FALSE; |
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56 | |||
57 | /* Initialize a memory manager instance for this object */ |
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58 | jinit_memory_mgr((j_common_ptr) cinfo); |
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59 | |||
60 | /* Zero out pointers to permanent structures. */ |
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61 | cinfo->progress = NULL; |
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62 | cinfo->dest = NULL; |
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63 | |||
64 | cinfo->comp_info = NULL; |
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65 | |||
66 | for (i = 0; i < NUM_QUANT_TBLS; i++) |
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67 | cinfo->quant_tbl_ptrs[i] = NULL; |
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68 | |||
69 | for (i = 0; i < NUM_HUFF_TBLS; i++) { |
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70 | cinfo->dc_huff_tbl_ptrs[i] = NULL; |
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71 | cinfo->ac_huff_tbl_ptrs[i] = NULL; |
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72 | } |
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73 | |||
74 | cinfo->script_space = NULL; |
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75 | |||
76 | cinfo->input_gamma = 1.0; /* in case application forgets */ |
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77 | |||
78 | /* OK, I'm ready */ |
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79 | cinfo->global_state = CSTATE_START; |
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80 | } |
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81 | |||
82 | |||
83 | /* |
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84 | * Destruction of a JPEG compression object |
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85 | */ |
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86 | |||
87 | GLOBAL(void) |
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88 | jpeg_destroy_compress (j_compress_ptr cinfo) |
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89 | { |
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90 | jpeg_destroy((j_common_ptr) cinfo); /* use common routine */ |
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91 | } |
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92 | |||
93 | |||
94 | /* |
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95 | * Abort processing of a JPEG compression operation, |
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96 | * but don't destroy the object itself. |
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97 | */ |
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98 | |||
99 | GLOBAL(void) |
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100 | jpeg_abort_compress (j_compress_ptr cinfo) |
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101 | { |
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102 | jpeg_abort((j_common_ptr) cinfo); /* use common routine */ |
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103 | } |
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104 | |||
105 | |||
106 | /* |
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107 | * Forcibly suppress or un-suppress all quantization and Huffman tables. |
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108 | * Marks all currently defined tables as already written (if suppress) |
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109 | * or not written (if !suppress). This will control whether they get emitted |
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110 | * by a subsequent jpeg_start_compress call. |
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111 | * |
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112 | * This routine is exported for use by applications that want to produce |
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113 | * abbreviated JPEG datastreams. It logically belongs in jcparam.c, but |
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114 | * since it is called by jpeg_start_compress, we put it here --- otherwise |
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115 | * jcparam.o would be linked whether the application used it or not. |
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116 | */ |
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117 | |||
118 | GLOBAL(void) |
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119 | jpeg_suppress_tables (j_compress_ptr cinfo, boolean suppress) |
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120 | { |
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121 | int i; |
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122 | JQUANT_TBL * qtbl; |
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123 | JHUFF_TBL * htbl; |
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124 | |||
125 | for (i = 0; i < NUM_QUANT_TBLS; i++) { |
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126 | if ((qtbl = cinfo->quant_tbl_ptrs[i]) != NULL) |
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127 | qtbl->sent_table = suppress; |
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128 | } |
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129 | |||
130 | for (i = 0; i < NUM_HUFF_TBLS; i++) { |
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131 | if ((htbl = cinfo->dc_huff_tbl_ptrs[i]) != NULL) |
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132 | htbl->sent_table = suppress; |
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133 | if ((htbl = cinfo->ac_huff_tbl_ptrs[i]) != NULL) |
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134 | htbl->sent_table = suppress; |
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135 | } |
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136 | } |
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137 | |||
138 | |||
139 | /* |
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140 | * Finish JPEG compression. |
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141 | * |
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142 | * If a multipass operating mode was selected, this may do a great deal of |
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143 | * work including most of the actual output. |
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144 | */ |
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145 | |||
146 | GLOBAL(void) |
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147 | jpeg_finish_compress (j_compress_ptr cinfo) |
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148 | { |
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149 | JDIMENSION iMCU_row; |
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150 | |||
151 | if (cinfo->global_state == CSTATE_SCANNING || |
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152 | cinfo->global_state == CSTATE_RAW_OK) { |
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153 | /* Terminate first pass */ |
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154 | if (cinfo->next_scanline < cinfo->image_height) |
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155 | ERREXIT(cinfo, JERR_TOO_LITTLE_DATA); |
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156 | (*cinfo->master->finish_pass) (cinfo); |
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157 | } else if (cinfo->global_state != CSTATE_WRCOEFS) |
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158 | ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state); |
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159 | /* Perform any remaining passes */ |
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160 | while (! cinfo->master->is_last_pass) { |
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161 | (*cinfo->master->prepare_for_pass) (cinfo); |
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162 | for (iMCU_row = 0; iMCU_row < cinfo->total_iMCU_rows; iMCU_row++) { |
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163 | if (cinfo->progress != NULL) { |
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164 | cinfo->progress->pass_counter = (long) iMCU_row; |
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165 | cinfo->progress->pass_limit = (long) cinfo->total_iMCU_rows; |
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166 | (*cinfo->progress->progress_monitor) ((j_common_ptr) cinfo); |
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167 | } |
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168 | /* We bypass the main controller and invoke coef controller directly; |
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169 | * all work is being done from the coefficient buffer. |
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170 | */ |
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171 | if (! (*cinfo->coef->compress_data) (cinfo, (JSAMPIMAGE) NULL)) |
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172 | ERREXIT(cinfo, JERR_CANT_SUSPEND); |
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173 | } |
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174 | (*cinfo->master->finish_pass) (cinfo); |
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175 | } |
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176 | /* Write EOI, do final cleanup */ |
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177 | (*cinfo->marker->write_file_trailer) (cinfo); |
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178 | (*cinfo->dest->term_destination) (cinfo); |
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179 | /* We can use jpeg_abort to release memory and reset global_state */ |
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180 | jpeg_abort((j_common_ptr) cinfo); |
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181 | } |
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182 | |||
183 | |||
184 | /* |
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185 | * Write a special marker. |
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186 | * This is only recommended for writing COM or APPn markers. |
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187 | * Must be called after jpeg_start_compress() and before |
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188 | * first call to jpeg_write_scanlines() or jpeg_write_raw_data(). |
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189 | */ |
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190 | |||
191 | GLOBAL(void) |
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192 | jpeg_write_marker (j_compress_ptr cinfo, int marker, |
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193 | const JOCTET *dataptr, unsigned int datalen) |
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194 | { |
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195 | JMETHOD(void, write_marker_byte, (j_compress_ptr info, int val)); |
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196 | |||
197 | if (cinfo->next_scanline != 0 || |
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198 | (cinfo->global_state != CSTATE_SCANNING && |
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199 | cinfo->global_state != CSTATE_RAW_OK && |
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200 | cinfo->global_state != CSTATE_WRCOEFS)) |
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201 | ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state); |
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202 | |||
203 | (*cinfo->marker->write_marker_header) (cinfo, marker, datalen); |
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204 | write_marker_byte = cinfo->marker->write_marker_byte; /* copy for speed */ |
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205 | while (datalen--) { |
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206 | (*write_marker_byte) (cinfo, *dataptr); |
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207 | dataptr++; |
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208 | } |
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209 | } |
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210 | |||
211 | /* Same, but piecemeal. */ |
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212 | |||
213 | GLOBAL(void) |
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214 | jpeg_write_m_header (j_compress_ptr cinfo, int marker, unsigned int datalen) |
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215 | { |
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216 | if (cinfo->next_scanline != 0 || |
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217 | (cinfo->global_state != CSTATE_SCANNING && |
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218 | cinfo->global_state != CSTATE_RAW_OK && |
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219 | cinfo->global_state != CSTATE_WRCOEFS)) |
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220 | ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state); |
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221 | |||
222 | (*cinfo->marker->write_marker_header) (cinfo, marker, datalen); |
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223 | } |
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224 | |||
225 | GLOBAL(void) |
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226 | jpeg_write_m_byte (j_compress_ptr cinfo, int val) |
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227 | { |
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228 | (*cinfo->marker->write_marker_byte) (cinfo, val); |
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229 | } |
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230 | |||
231 | |||
232 | /* |
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233 | * Alternate compression function: just write an abbreviated table file. |
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234 | * Before calling this, all parameters and a data destination must be set up. |
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235 | * |
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236 | * To produce a pair of files containing abbreviated tables and abbreviated |
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237 | * image data, one would proceed as follows: |
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238 | * |
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239 | * initialize JPEG object |
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240 | * set JPEG parameters |
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241 | * set destination to table file |
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242 | * jpeg_write_tables(cinfo); |
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243 | * set destination to image file |
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244 | * jpeg_start_compress(cinfo, FALSE); |
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245 | * write data... |
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246 | * jpeg_finish_compress(cinfo); |
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247 | * |
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248 | * jpeg_write_tables has the side effect of marking all tables written |
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249 | * (same as jpeg_suppress_tables(..., TRUE)). Thus a subsequent start_compress |
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250 | * will not re-emit the tables unless it is passed write_all_tables=TRUE. |
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251 | */ |
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252 | |||
253 | GLOBAL(void) |
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254 | jpeg_write_tables (j_compress_ptr cinfo) |
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255 | { |
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256 | if (cinfo->global_state != CSTATE_START) |
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257 | ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state); |
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258 | |||
259 | /* (Re)initialize error mgr and destination modules */ |
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260 | (*cinfo->err->reset_error_mgr) ((j_common_ptr) cinfo); |
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261 | (*cinfo->dest->init_destination) (cinfo); |
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262 | /* Initialize the marker writer ... bit of a crock to do it here. */ |
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263 | jinit_marker_writer(cinfo); |
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264 | /* Write them tables! */ |
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265 | (*cinfo->marker->write_tables_only) (cinfo); |
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266 | /* And clean up. */ |
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267 | (*cinfo->dest->term_destination) (cinfo); |
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268 | /* |
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269 | * In library releases up through v6a, we called jpeg_abort() here to free |
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270 | * any working memory allocated by the destination manager and marker |
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271 | * writer. Some applications had a problem with that: they allocated space |
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272 | * of their own from the library memory manager, and didn't want it to go |
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273 | * away during write_tables. So now we do nothing. This will cause a |
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274 | * memory leak if an app calls write_tables repeatedly without doing a full |
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275 | * compression cycle or otherwise resetting the JPEG object. However, that |
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276 | * seems less bad than unexpectedly freeing memory in the normal case. |
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277 | * An app that prefers the old behavior can call jpeg_abort for itself after |
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278 | * each call to jpeg_write_tables(). |
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279 | */ |
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280 | }>>>>>> |